Médigue C, Viari A, Hénaut A, Danchin A
Section Physique-Chimie, Institut Curie, Paris, France.
Mol Microbiol. 1991 Nov;5(11):2629-40. doi: 10.1111/j.1365-2958.1991.tb01972.x.
The DNA sequence data for Escherichia coli deposited in the EMBL library (release 27), together with miscellaneous data obtained from several laboratories, have been localized on an updated and corrected version of the restriction map of the chromosome generated by Kohara et al. (1987) and modified by others. This second update adds a further 500 kbp, increasing the amount of the E. coli chromosome sequenced to about one third of the total: 1510 kbp of sequenced DNA is included in the present data base. The accuracy of the map is assessed, and allows us to propose a precise genetic map position for every sequenced gene. The location of rare-cutting sites such as AvrII, NotI and SfiI have also been included in the update in order to combine the data obtained from different sources into one single file. The distribution of palindromic sequences (to which most restriction sites belong) has been studied in coding sequences. There appears to be a significant counter-selection against several such sequences in E. coli coding sequences (but not in other organisms such as Saccharomyces cerevisiae), suggesting the existence of constraints on DNA structure in E. coli, perhaps indicative of a functional role for horizontal gene transfer, preserving coding sequences, in this type of bacteria.
存于EMBL文库（第27版）中的大肠杆菌DNA序列数据，连同从几个实验室获得的其他各类数据，已定位到由Kohara等人（1987年）绘制并经他人修改的染色体限制性图谱的更新校正版本上。此次第二次更新增加了另外500千碱基对，使已测序的大肠杆菌染色体数量增加到总数的约三分之一：当前数据库包含1510千碱基对的已测序DNA。对该图谱的准确性进行了评估，这使我们能够为每个已测序基因提出精确的遗传图谱位置。诸如AvrII、NotI和SfiI等稀有切割位点的位置也已包含在此次更新中，以便将从不同来源获得的数据整合到一个单一文件中。对编码序列中回文序列（大多数限制位点所属）的分布进行了研究。在大肠杆菌编码序列中似乎对几种此类序列存在显著的反向选择（但在酿酒酵母等其他生物体中不存在），这表明大肠杆菌中DNA结构存在限制，这可能表明水平基因转移在这类细菌中对保留编码序列具有功能性作用。
